This invention is generally directed to an emergency brake lamp illumination system for a trailer. More particularly, the present invention contemplates a system which will illuminate the brake lamps on a tractor-trailer when the emergency brake is applied.
A standard tractor-trailer, uses two braking systems, a primary service brake and a secondary emergency/parking brake.
The primary service brake is a fully pneumatic system, using air pressure for signaling the application of the brakes. Federally required brake lamps on the trailer are used to indicate primary service brake application. The brake lamps are controlled by a pneumatic pressure switch mounted on the tractor and connected to the service brake control line. Thus, when the service brake is applied, a pneumatic pressure switch closes, completing the electrical circuit to the brake lamps mounted on the tractor and continuing through the electrical connection to the brake lamps on the trailer.
The secondary emergency/parking brake uses the loss of air to signal the application of a spring to apply the brakes. Thus, if air pressure in the braking system is lost, the emergency brake will automatically cause large springs on the brakes to apply the brakes to stop the trailer.
The problem with this braking system is that the brake lamps are not activated when the emergency brake is applied. Upon an emergency brake activation, the driver of the vehicle following the tractor-trailer does not have warning that the tractor-trailer is rapidly coming to a stop. It is obvious what can happen when a tractor-trailer stops rapidly without warning the driver behind.
The present invention provides an emergency brake lamp illumination system which overcomes the problems presented in the prior art and which provides additional advantages over the prior art, such advantages will become clear upon a reading of the attached specification in combination with a study of the drawings.
A general object of the present invention is to provide an emergency brake lamp illumination system for a trailer which will cause brake lamps on the trailer to illuminate when the emergency brakes are applied.
Another object of the present invention is to provide an emergency brake lamp illumination system which uses a pressure switch to sense pressure within the emergency braking system.
A specific object of the present invention is to provide an emergency brake lamp illumination system which uses a pressure switch to provide power to the brake lamps when the emergency brakes are applied.
Briefly, and in accordance with the foregoing, the present invention discloses an emergency brake lamp illumination system which senses pressure in the emergency braking system by using a normally-closed pneumatic-activated electrical switch. When power is supplied to the trailer, pressure will exist in the emergency braking system causing the pneumatic switch to open. If pressure is lost in the emergency braking system, this loss of pressure signals the application of a spring to apply the brakes. In addition, the loss of pressure causes the pressure switch to close and results in power being supplied to the brake lamps for illumination.